The present invention relates to fluid-operated gear motors.
It is known to provide fluid-operated gear motors wherein at least at one axial end face of the gears there are provided sealing elements which engage this axial end face and which are pressed against the same by fluid pressure fields. In these machines of the prior art the forces acting from the fluid pressure fields upon the sealing elements, which can also be journalling elements for the gears, must be greater than those forces which develop in the interior of the motor and tend to lift or move the gears away from these sealing elements. Unless this relationship exists, there will be no proper sealing action and an excessive amount of fluid leakage will develop. When such motors are not in operation, that is when the gears are stationary, the frictional forces acting upon the gears are much higher -- due to the existing static friction -- then when the gears are in rotation. This means that when such a motor is started up, it can start up only slowly and in some instances the frictional forces may be so high that starting of the gears in rotation may even be blocked. It is evident that this is highly disadvantageous; nevertheless, to a greater or lesser degree substantially all gear motors of the prior art which are constructed as outlined above, are subject to this disadvantage.